scholarly journals Acid deposition, land-use change and global change: MAGIC 7 model applied to Aber, UK (NITREX project) and Risdalsheia, Norway (RAIN and CLIMEX projects)

1998 ◽  
Vol 2 (4) ◽  
pp. 385-397 ◽  
Author(s):  
R. F. Wright ◽  
B. A. Emmett ◽  
A. Jenkins
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Acid Deposition ◽  
Base Cations ◽  
Nitrogen Addition ◽  
Scale Model ◽  
N Leaching ◽  
Catchment Scale ◽  
Acid Neutralising Capacity ◽  
Potential Tool

Abstract. Nitrogen processes are now included in a new version of MAGIC (version 7), a process-oriented catchment-scale model for simulating runoff chemistry. Net retention of nitrogen (N) is assumed to be controlled by plant uptake and the carbon/nitrogen (C/N) ratio of soil organic matter, the latter as evidenced by empirical data from forest stands in Europe. The ability of this version of MAGIC 7 to simulate and predict inorganic N concentrations in runoff is evaluated by means of data from whole-ecosystem manipulation experiments at Aber, Wales, UK, (nitrogen addition as part of the NITREX project) and Risdalsheia, Norway (exclusion of acid deposition as part of the RAIN project and climate change as part of the CLIMEX project). MAGIC 7 simulated the changes in N leaching satisfactorily as well as changes in base cations and acid neutralising capacity observed at these two sites. MAGIC 7 offers a potential tool for regional assessments and scenario studies of the combined effects of acid deposition, land-use and climate change.

scholarly journals Norwegian lakes show widespread recovery from acidification; results from national surveys of lakewater chemistry 1986-1997

1998 ◽  
Vol 2 (4) ◽  
pp. 555-562 ◽  
Author(s):  
B. L. Skjelkvåle ◽  
R. F. Wright ◽  
A. Henriksen
Keyword(s):  
Base Cations ◽  
Chemical Recovery ◽  
N Leaching ◽  
National Scale ◽  
Western Norway ◽  
Acid Neutralising Capacity ◽  
Recovery From Acidification ◽  
Lakewater Chemistry ◽  
Southern Norway ◽  
Eastern Norway

Abstract. Surveys of 485 lakes in Norway conducted in 1986 and again in 1995 reveal widespread chemical recovery from acidification. Sulphate concentrations in lakes have decreased by 40% in acidified areas in southern Norway. This decrease has been compensated about 25% by decreases in concentrations of base cations and of 75% by increased Acid Neutralising Capacity (ANC). The increased ANC in turn reflects lower concentrations of acidic cations Aluminum (ALn+) and Hydrogen (H+). A sub-set of 78 of the 485 lakes sampled yearly between 1986 and 1997 shows that, at first most of the decrease in non-marine sulphate (SO4*) was compensated by a decrease in base cations, such that ANC remained unchanged. Then as SO4* continued to decrease, the concentrations of non- marine calcium and magnesium ((Ca+Mg)*) levelled out. Consequently, ANC increased, and H+ and Aln+ started to decrease. In eastern Norway, this shift occurred in 1989–90, and came slightly later in southern and western Norway. Similar shifts in trends in about 1991–92 can also be seen in the non-acidified areas in central and northern Norway. This shift in trends is not as pronounced in western Norway, perhaps because of the confounding influence of sea-salt episodes on water chemistry. This is the first documented national-scale recovery from acidification due to reduced acid deposition. Future climate warming and potentially increased N-leaching can counteract the positive trends in recovery from acidification.

scholarly journals Drought Risk under Climate and Land Use Changes: Implication to Water Resource Availability at Catchment Scale

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1790 ◽  
Author(s):  
Muhammad Afzal ◽  
Ragab Ragab
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Groundwater Recharge ◽  
Land Use Changes ◽  
Future Climate Change ◽  
Emission Scenarios ◽  
Catchment Scale ◽  
High Emission ◽  
The Impact

Although the climate change projections are produced by global models, studying the impact of climatic change on water resources is commonly investigated at catchment scale where the measurements are taken, and water management decisions are made. For this study, the Frome catchment in the UK was investigated as an example of midland England. The DiCaSM model was applied using the UKCP09 future climate change scenarios. The climate projections indicate that the greatest decrease in groundwater recharge and streamflow was projected under high emission scenarios in the 2080s. Under the medium and high emission scenarios, model results revealed that the frequency and severity of drought events would be the highest. The drought indices, the Reconnaissance Drought Index, RDI, Soil Moisture Deficit, SMD and Wetness Index, WI, predicted an increase in the severity of future drought events under the high emission scenarios. Increasing broadleaf forest area would decrease streamflow and groundwater recharge. Urban expansion could increase surface runoff. Decreasing winter barley and grass and increasing oil seed rape, would increase SMD and slightly decrease river flow. Findings of this study are helpful in the planning and management of the water resources considering the impact of climate and land use changes on variability in the availability of surface and groundwater resources.

RAIN Project: Results after 8 Years of Experimentally Reduced Acid Deposition to a Whole Catchment

1993 ◽  
Vol 50 (2) ◽  
pp. 258-268 ◽  
Author(s):  
Richard F. Wright ◽  
Erik Lotse ◽  
Arne Semb
Keyword(s):  
Acid Deposition ◽  
Soil Chemistry ◽  
Nitrogen Saturation ◽  
Base Cations ◽  
Strong Acid ◽  
Catchment Scale ◽  
Exclusion Experiment ◽  
Surface Water Chemistry ◽  
Southern Norway

At Risdalsheia (southern Norway), an ongoing catchment-scale acid-exclusion experiment has been conducted since 1984 as part of the RAIN project (Reversing Acidification In Norway). Acid precipitation is collected on a 1200-m2 transparent roof, treated by ion exchange, sea salts readded, and reapplied as clean rain beneath the roof Up to 1990 annual surveys of soil chemistry have revealed no significant trends. The chemical composition of runoff has changed: sulfate decreased from about 111 μeq/L in 1984 to 38 μeq/L in 1992 and nitrate from about 33 to 5 μeq/L. Base cations decreased and alkalinity increased over the 8-yr period from −88 to −29 μeq/L to compensate for this change in strong acid anions. Much of the alkalinity change is due to the increased role of organic anions. The results fit an empirical nomograph relating alkalinity, base cations, and strong acid anions and a new empirical nomograph relating alkalinity, H+, and total organic carbon. The acid-exclusion experiment provides the first catchment-scale evidence for the reversibility of nitrogen saturation; RAIN results corroborate field observations of changes in surface water chemistry in response to reduced acid deposition as well as process-oriented, conceptual acidification models.

scholarly journals Nitrogen Risk Assessment Model for Scotland: I. Nitrogen leaching

2004 ◽  
Vol 8 (2) ◽  
pp. 191-204 ◽  
Author(s):  
S. M. Dunn ◽  
A. J. A. Vinten ◽  
A. Lilly ◽  
J. DeGroote ◽  
M. A. Sutton ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Land Use ◽  
Policy Development ◽  
Agricultural Land ◽  
Growing Season ◽  
Assessment Model ◽  
N Leaching ◽  
Risk Assessment Model ◽  
Catchment Scale ◽  
Residual N

Abstract. The Nitrogen Risk Assessment Model for Scotland (NIRAMS) has been developed for prediction of streamwater N concentrations draining from agricultural land in Scotland. The objective of the model is to predict N concentrations for ungauged catchments, to fill gaps in monitoring data and to provide guidance in relation to policy development. The model uses nationally available data sets of land use, soils, topography and meteorology and has been developed within a Geographic Information System (GIS). The model includes modules to calculate N inputs to the land, residual N remaining at the end of the growing season, weekly time-series of leached N and transport of N at the catchment scale. This paper presents the methodology for calculating N balances for different land uses and for predicting the time sequence of N leaching after the end of the growing season. Maps are presented of calculated residual N and N leaching for the whole of Scotland and the spatial variability in N leaching is discussed. The results demonstrate the high variability in N leaching across Scotland. The simulations suggest that, in the areas with greatest residual N, the losses of N are not directly proportional to the amount of residual N, because of their coincidence with lower rainfall. In the companion paper, the hydrological controls on N transport within NIRAMS are described, and results of the full model testing are presented. Keywords: nitrogen, diffuse pollution, agriculture, leaching, land use, model, national, catchment

scholarly journals From field to stream: Tracing streambed organic carbon origins at a catchment scale

2021 ◽  
Author(s):  
Katy Wiltshire ◽  
Miriam Glendell ◽  
Toby Waine ◽  
Robert Grabowski ◽  
Barry Thornton ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Organic Carbon ◽  
Soil Loss ◽  
Sediment Fingerprinting ◽  
Catchment Scale ◽  
Erosion Modelling ◽  
River Corridor ◽  
Soil Loss Equation ◽  
Unmixing Model

<p>Quantifying organic carbon (OC) levels and the processes altering them is key in unlocking soils potential as a mediator of climate change through sequestration of atmospheric CO<sub>2</sub>. In areas of high soil erosion increased fluxes of OC across the terrestrial-aquatic interface are likely and understanding these fluxes is crucial in integrating lateral OC fluxes within the carbon cycle. For this study of a small UK catchment, OC mapping and Revised Universal Soil Loss Equation (RUSLE) based erosion modelling provided estimates of proportional soil OC loss coming from each land use. Sediment fingerprinting using <em>n</em>-alkane biomarkers and a Bayesian unmixing model provided a comparison of streambed OC proportions by land use to assess which processes were dominating OC input to streams. Results showed that RUSLE-based soil OC loss proportions exhibited disconnect with sediment fingerprinting OC composition and the river corridor and riparian environment were key zones in regulating terrestrial to aquatic fluxes of OC.</p>

Modelling nitrate losses from agricultural activities on a national scale

2005 ◽  
Vol 51 (3-4) ◽  
pp. 319-327 ◽  
Author(s):  
S.M. Dunn ◽  
A.J.A. Vinten ◽  
A. Lilly ◽  
J. DeGroote ◽  
M. McGechan
Keyword(s):  
Land Use ◽  
Policy Development ◽  
Agricultural Land ◽  
Transport Model ◽  
Geographic Location ◽  
Assessment Model ◽  
Balance Model ◽  
N Leaching ◽  
Catchment Scale ◽  
Ungauged Catchments

The Nitrogen Risk Assessment Model for Scotland (NIRAMS) has been developed as a screening tool for prediction of streamwater N concentrations draining from agricultural land in Scotland. The objective of the model is to be able to predict N concentrations for ungauged catchments, to fill gaps in monitoring data and provide guidance in relation to policy development. The model uses national land use, soils and meteorology data sets and has been developed within an ArcView GIS user interface. The model includes modules to calculate N inputs to the land, residual N remaining at the end of the growing season, weekly time-series of leached N and transport of N at the catchment scale. The N leaching and transport are controlled by hydrological modules, including a national water balance model and a catchment scale transport model. Preliminary testing of NIRAMS has been carried out on eight Scottish catchments, diverse in terms of geographic location as well as land use. The model is capable of predicting the correct mean level of stream N concentrations, as well as the basic characteristics of seasonal variation. As such the model can be of value for providing estimates of N concentrations in ungauged areas.

scholarly journals Climate change as a confounding factor in reversibility of acidification: RAIN and CLIMEX projects

2001 ◽  
Vol 5 (3) ◽  
pp. 477-486 ◽  
Author(s):  
R. F. Wright ◽  
A. Jenkins
Keyword(s):  
Climate Change ◽  
Acid Deposition ◽  
Forest Canopy ◽  
Inorganic Nitrogen ◽  
Sea Salt ◽  
Related Factors ◽  
Run Off ◽  
Acid Neutralising Capacity ◽  
Sulphate Deposition ◽  
Recovery From Acidification

Abstract. The RAIN and CLIMEX experiments at Risdalsheia, southernmost Norway, together cover 17 years (1984-2000) of whole-catchment manipulation of acid deposition and climate. A 1200 m2 roof placed over the forest canopy at KIM catchment excluded about 80% of ambient acid deposition; clean rain was sprinkled under the roof. A climate change treatment (3.7°C increase in air temperature and increase in air carbon dioxide concentrations to 560 ppmv) was superimposed on the clean rain treatment for four years (1995-1998). Sea-salt inputs and temperature are climate-related factors that influence water chemistry and can confound long-term trends caused by changes in deposition of sulphur and nitrogen. The RAIN and CLIMEX experiments at Risdalsheia provided direct experimental data that allow quantitative assessment of these factors. Run-off chemistry responded rapidly to the decreased acid deposition. Sulphate concentrations decreased by 50% within three years; nitrate and ammonium concentrations decreased to new steady-state levels within the first year. Acid neutralising capacity increased and hydrogen ion and inorganic aluminium decreased. Similar recovery from acidification was also observed at the reference catchment, ROLF, in response to the general 50% reduction in sulphate deposition over southern Norway in the late 1980s and 1990s. Variations in sea-salt deposition caused large variations in run-off chemistry at the reference catchment ROLF and the year-to-year noise in acid neutralising capacity was as large as the overall trend over the period. These variations were absent at KIM catchment because the sea-salt inputs were held constant over the entire 17 years of the clean rain treatment. The climate change experiment at KIM catchment resulted in increased leaching of inorganic nitrogen, probably due to increased mineralisation and nitrification rates in the soils. Keywords: acid deposition, global change, water, soil, catchment, experiment, Norway.

scholarly journals Drivers, Impacts and Mitigation of Increased Sedimentation in the Hydropower Reservoirs of East Africa

Land ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 638
Author(s):  
Aloyce Amasi ◽  
Maarten Wynants ◽  
William Blake ◽  
Kelvin Mtei
Keyword(s):  
Climate Change ◽  
Land Use ◽  
East Africa ◽  
Deep Understanding ◽  
Scientific Data ◽  
Sediment Budget ◽  
Catchment Scale ◽  
Sediment Budgets ◽  
Selection Of ◽  
Hydropower Reservoirs

Hydropower reservoirs are essential for the climate-neutral development of East Africa. Hydropower production, however, is threatened by human activities that lead to a decrease in water storage capacity of reservoirs. Land use/land cover and climatic changes are driving accelerated soil erosion in semi-arid East Africa, which ultimately increases reservoir sedimentation and decreases energy production. Sediment delivery dynamics at the catchment scale are complex, involving the interaction of multiple factors and processes on different spatial and temporal scales. A lack of understanding of these processes and their interactions may impede the efficiency of sediment mitigation and control strategies. A deep understanding of the processes of erosion and connectivity of the land to river channel, as well as storage of eroded material within hillslopes and floodplains, and sediment accumulation in the reservoirs supports selection of future dam locations and sustainable management of reservoirs. The sediment budget approach can provide such a holistic perspective by accounting for the various sediment sources, transport, sinks, and redistribution when the sediment is routed through that catchment. Constructing sediment budgets is challenging, but the potential for integrating a number of different techniques offers new opportunities to collect the required information. In East Africa, the spatial planning of dams is mainly dominated by political and financial motives, and impacts of land use and climate on the sediment transport dynamics are not adequately considered. Production of sediment budgets under different scenarios of land use and climate change should be an essential step when deciding the location and management strategies for dams. Selection of new hydroelectric reservoir sites must consider long-term scientific data on climate change, and the sediment budget components for sustainable land management planning, hydropower sustainability.

scholarly journals Climate change adaptation in arable land use, and impact on nitrogen load at catchment scale in northern agriculture

2013 ◽  
Vol 22 (3) ◽  
pp. 342-355 ◽  
Author(s):  
Katri Rankinen ◽  
Pirjo Peltonen-Sainio ◽  
Kirsti Granlund ◽  
Hannu Ojanen ◽  
Mikko Laapas ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Crop Production ◽  
Nutrient Loading ◽  
Arable Land ◽  
System Level ◽  
Adaptation To Climate Change ◽  
Catchment Scale ◽  
Land Use Patterns ◽  
Arable Land Use

Prolongation of the growing season due to a warming climate could represent new opportunities for northern agriculture. Climatic and biotic constraints may challenge future crop production. The objective of this study was to speculate how a range of arable land use patterns, resulting from various policy driven choices, could be introduced into a farming system, and how they would affect the risks associated with nutrient leaching. We found that while adaptation to climate change must include consideration of crop choices, there are conflicts associated with allocations and rotations for various market and policy situations. The expected increase in nutrient loading in the simulations caused by climate change was moderate. The increase can partly be compensated for by changes in farmland use, more in the shorter term than in the longer term to mid-century. In the future, adaptation at cropping system level is potentially an efficient way to manage nutrient load risks.

SOL40: forty years of simulations under a climate and land use change scenario 

2021 ◽  
Author(s):  
Alessandro Ceppi ◽  
Enrico Gambini ◽  
Gabriele Lombardi ◽  
Giovanni Ravazzani ◽  
Marco Mancini
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Curve Number ◽  
Change Scenario ◽  
Catchment Scale ◽  
Physically Based ◽  
Anthropogenic Development ◽  
Meteoric Precipitation ◽  
The Impact

<p>Nowadays, one major issue concerns the land-use change due to urban developments that alters the basin response to meteorological events. With less storage capacity and more rapid runoff, urban river basins rise more quickly during storms and have higher peak discharge rates than rural catchments.</p><p>An exemplary case of this situation is the city of Milan and its whole territory that extends towards north that collects meteoric precipitation, through the Seveso, Olona and Lambro (SOL) rivers plus a number of minor tributaries for a total drainage surface of about 1300 km<sup>2</sup>.</p><p>In order to assess the impact of anthropogenic development on urban catchment scale hydrology, a reanalysis of 40 years of simulations has been carried out with the Curve Number (CN) map based on current land use, and compared to simulations with the CN maps derived using past land use.</p><p>A coupled hydro-meteorological system which comprises the physically based rainfall-runoff hydrological model FEST-WB, developed by the Politecnico di Milano and the ERA5-Land hourly dataset from 1981 to present, provided by ECMWF under the framework of Copernicus Climate Change Service Programme has been built.</p><p>The study (named as SOL40) exactly analyses 40-years trends of the main meteorological (air temperature, precipitation, etc.) and hydrological variables (soil moisture, evapotranspiration and runoff) over the SOL area, and try to quantify and separate the impact of land use change from the climate change scenario.</p>

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